The report presents the findings of an epidemiologic study of cataract in Shunyi County, Beijing, conducted in 1985, revealing that the general prevalence of senile cataract was 5.99%, and in people over 40 years of age, 18.58%; the rate obviously increased with age. Cataract accounted for 14.54% of the blind and 20.51% of the low-vision. The diagnostic criteria for senile cataract in surveys and the strategy for the prevention and treatment of senile cataract are recommended.